Electrical terminal



M. 10, 1970 V H. wosn'rz I snowmen TERMINAL Fund New. 4. 196B 'mwsm.

MMMEI a:

INVENTOR.

Ham; Wdcriz 3,539,977 ELECTRICAL TERMINAL Hans Woertz, Basel,Switzerland, assignor t Oskar Woertz, Inh. H. & O. Woertz, Basel,Switzerland Filed Nov. 4, 1968, Ser. No. 773,154

Claims priority, application Switzerland, Nov. 13, 1967,

Int. Cl. H01r 7/14, 9/12 US. Cl. 339-198 2 Claims ABSTRACT OF THEDISCLOSURE An electrical terminal for securing a conductor theretohaving a casing with a pressure member therein and a spring elementhaving longitudinal edge portions and a saddle-shaped configurationmounted in the casing.

This invention relates to an electrical terminal to secure conductorsthereto.

The present invention relates to an electric terminal comprising,between a pressure member and a supporting surface, a chamber foraccommodating one or more conductors, and comprising a spring elementwhich forms a boundary surface of said chamber and which is made from astrip of resilient material.

In known terminals of the stated kind, wherein conductors are clampedbetween a leaf spring, which is curved in the unloaded condition in thelongitudinal direction and bears upon a supporting surface, and apressure member, having a flat pressure surface and subjected topressure from a screw, there exists the danger that with two roundconductors of dissimilar diameter, only that conductor having thegreater diameter will be properly clamped, and the conductor having thesmaller diameter will be inefficiently clamped, or not clamped at all.

The object of the invention resides essentially in eliminating thestated disadvantage and in providing a terminal of the kind that is sodesigned that even an individual conductor can be clamped in a definiteand secure position.

In accordance with the invention, this latter is achieved essentially byat least single longitudinal edge portions of the spring elements, whichare located in the zone of action of the pressure member, and projectingtowards the conductor-receiving chamber in such a manner that thatsurface of the spring element presented to the chamber has the form of aV, open toward the chamber, in the vertical projection and in thelongitudinal direction of the spring element.

Further objects will be apparent from the following description whenconsidered in connection with the accompanying drawing in which:

FIG. 1 is a part side elevation and part sectional view of a terminal;

FIG. 2 is a section taken on line IIII of FIG. 1, in the direction ofthe arrows; and

FIG. 3 is a side view partly in section showing two terminals which arecontained in an insulating body and have, as a pressure member, a webcommon to both of them.

The terminal in FIGS. 1 and 2 has a conductor-receiving element orcasing 10, which is in the form of a piece of rectangular tubing.Inserted into the cavity 11 of the conductor-receiving element arerod-shaped pressure member 12 of rectangular cross-section and a springelement 13. Positioned between the pressure member 12 and the springelement 13 is the conductor-receiving chamber 14, into which one or moreelectric conductors can be pushed. A screw 15 acts upon that face of thepressure member 12 remote from the spring element 13, and this screwelement is contained in a taped hole 16 in one of United States Patent@flice 3,539,977 Patented Nov. 10, 1970 the narrow sides of theconductor-receiving element 10.

The spring element 13 is made from a strip of resilient material and issaddle-shaped in the zone of action of the pressure member 12, thelongitudinal edge portions 17 and 18 of the spring element 13 being bentupwards toward the chamber 14, so that the spring element 13, in thezone of action of the pressure member 12, is of V-shaped crosssectionopen towards the conductor-receiving chamber. By saddle-shaped is meantthat the spring element 13 has a double curved shape in the zone ofaction of which one curve being in the longitudinal direction of theelement and the other being in the transverse direction, Instead ofbeing formed into a V-shaped cross-section in the entire zone of actionof the pressure member 12, the spring element 13 can be so shaped inthis zone that only individual longitudinal edge portions project towardthe chamber 14, so that that surface of the spring element presented tothe chamber 14 has the shape of a V, open toward the conductor-receivingchamber 14 in the vertical projection in the direction of the conductorsthat are to be pushed in. In a spring element of this type, the twolongitudinal edge portions, for example, can be corrugated, andcorrugation of one of the longitudinal edge portions being phasedoppositely, in the longitudinal direction, to the corrugation in theother portion.

In the present embodiment, the surface of the spring element 13, that ispresented to the conductor-accommodating chamber 14, contains notches(not illustrated) which extend transversely of the longitudinaldirection of the spring element 13. The notches are for the purpose ofincreasing the friction between the spring element 13 and the conductoror conductors to be clamped in the terminal.

In the unloaded condition, the spring element 13 lies on the outer edgesof the narrow inner face 19 of the conductor-receiving element 10,opposite the screw 15. Both end portions 20 and 21 of the element 13 arebent away from the pressure member 12. One end portion 20, whichembraces the conductor-receiving element 10, is bent round through anangle of almost so that the spring element 13 is thereby attached to theconductor-receiving element 10. The other end portion 21 of the element13 is bent at approximate right angles to the supporting surface 19 and,directly adjacent the point of bend 22, has two incisions or cut-outportions 23, which reduce the cross-section.

FIG. 3 shows two terminals, each as in FIG. 1, which are contained in aninsulating member 24 and which incorporate, as pressure members 12, aweb 25 which is common to both terminals. The terminal disposed on theleft in the insulating member 24, together with the conductor-receivingelement 10a, is thus completely enclosed, that is, theconductor-receiving element 10a is pulled up against the web 25 b meansof the screw 15, while the terminal shown on the right, together withthe conductor-receiving element 10b, is fully open and ready to receiveconductors. Pieces 26 of flexible insulating tubing are pushed over theend portions 21 of the spring elements 13, which portions are bent atapproximately rightangles. As can be seen from FIG. 3, the downwardlyangled end portions 21 of the spring elements 13 prevent unintentionalinsertion of conductors into the cavities 27 below theconductor-receiving elements 10a and 10b in the insulating member 24.The flexible insulating tubes 26, pushed over the end portions 21 of thespring elements 13, thereby perform the function of reducing the spacesbetween the longitudinal edges of the angled end portions 21 and theinner face of the side wall of the insulating member 24 and the outerface of the side wall of a closure member, not illustrated in thedrawing, or of an adjacent insulating member.

The way in which the terminal is used and works when clamping twoconductors of round cross-section and dis- 12 and the spring element 13.

similar diameters, 'the sum of which is less than the width of thechamber in "which they are received, is"a's follows: with the terminalopen, the two conductors are inserted side-by-side into the chamber 14.The thicker conductor, for example, thereby lies on the longitudinaledge portion 17 and the thinner conductor on the other longitudinal edgeportion 18 of the spring element 13. When the screw is tightened,pressure is first applied, by way of the pressure member 12 and thethicker conductor, to the longitudinal edge portion 17 of the springelement 13 and this edge portion is pressed toward the supportingsurface 19 of the conductor-receiving element 10. As a result of thelateral play of the spring element 13 in the conductor-receiving element10, the spring element 13 tilts on the" supporting surface 19 in such away thatthe other;longitudinal edge portion 18 is pressed upwardsagainst 'the thinner conductor. In this way, the thinner conductor isalso clamped between the pressure member The'spring element 13 thus notonly performs the function of a safety means for preventing loosening ofa tightened screw 15, but it also takes over the role of matchingtliecross-section of the conductor-receiving chamber to thecross-sectionalforms of the conductors that are to be clamped. p g I 1 Since, when thespring element 13 tilts on the supporting surface 19, as described, theangled end portion 21 of the'spring element '13 is swung out of itsoriginal posi tion, there exists the danger of the end portion 21 of thespring element 13 applying unwanted pressure on the sidewall'ofthe'insulating elements 24or of the required tilting of thespring element being partially impeded; In the present embodiment,this"dangeris'countered'by the cutout parts23 which 'i''duce thecross-section of the end portion 21 adjacent th'poiritof'bend 22 andwhich provide a nominal bending point which can be deformed even bysmall forces." I

Iclaim: I

1. Electric terminal comprising a casing having a supporting surface, apressure member in" the casing, said casing having a chamber forreceiving at least one conductor, and a spring element forming aboundary surface of the conductor-receiving"chamber and which is formedfrom a strip' of resilient material, said spring element havinglongitudinal edge portions which are located in a Zone of action of thepressure member and projecting'toward and into the conductor-receivingchamberso that a surface of the spring element presented to theconductor-receiving chamber having the form of a V, open toward theconductor-receiving chamber in the perpendicular projection as to thelongitudinal direction of the spring element, the spring element beingeurved' in the zone of action of the pressure member in the longitudinaldirection of the spring element.

2. Electric terminal comprising a casing having a supporting surface, apressure member in the casing, said casing having a chamber forreceiving at least one conductor, and a spring element forming aboundary surface of the conductor-receiving chamber and which is formedfrom a strip of resilient rn'aterial,'saidspring element havinglongitudinal edge portions which are. located in a zone of action of thepressure member a'nd'projecting toward and" into the conductor-receivingchamber so that a surface of the spring element presented to theconductor-receiving chamber having the form'of a V, open toward theconductor-receiving chamber" in the perpendicular pro-,

jection as to the longitudinal direction of the spring element, thespring element having an end portion bent away from the casing outside abearing surfaceof the casing at least approximately at right angles tosaid surface, and at least one of the longitudinal edges of thebent-away end portion having atleast one cut-out portion to reduce thecross-section thereof adjacent a point where the spring element is bent.

References Cited UNITED STATES PATENTS 6/1931 Bormann et al. 2,805,4029/1957 Lucal 339-14 2,950,457 8/1960 Slater 339-41 3,124,409 3/1964 Nisula., 339 41 I 3,246,283 4/1966 Huska p l; FOliEICihli PATENTS 736,8026/1943 Germany.

MARVIN A. CHAMPION, Primary Examiner R. A. HAFER, Assistant Examiner US.Cl. X.R. 339-252, 272

